I've been doing multiline support the way that wiring does: not explicitly configuring it that way, but allowing you to move the cursor to any line you want. I can write to all the lines on the 2 and 4 line displays I have.

gradbert: The constructor for the LiquidCrystal library on Arduino will be basically what you suggest. The rest of the API will mirror Wiring's, although we could certainly add some functions (either now or later).

gradbert

Ok, I figured code speaks louder than words, so I took the LCD4bit library and combined it with the code from SoftwareSerial. The constructor it the interface described previously. It has the most of the same print() and println() functions as SoftwareSerial. The print(uint8_t) is replaced with rprint(uint8_t). something with the casting was giving me grief. All the printing functions have been moved to a class called Printable. the LCDnew class only has to implement rprint(). I don't have the carrage return/line feed handling implemented in the LCD class yet.

gradbert: cool. I actually did something similar (see: http://svn.berlios.de/wsvn/arduino/trunk/hardware/cores/arduino/), but you've got some nice improvements. I like the name Printable better than Print, which is what I used. Also, did you get this to work on the Arduino? I had trouble getting virtual functions to compile, so I hacked together my own version.

gradbert

gradbert: cool. I actually did something similar (see: http://svn.berlios.de/wsvn/arduino/trunk/hardware/cores/arduino/), but you've got some nice improvements. I like the name Printable better than Print, which is what I used. Also, did you get this to work on the Arduino? I had trouble getting virtual functions to compile, so I hacked together my own version.

I did get it working. In the zip file is an example program that will compile, download, and display on an lcd. The only thing that was really giving me a problem was that the build doesn't seem to be very happy with a library including another library, so in my sketch I have to explicitly include <Printable.h>.

Now because the pin assignments are local to the instance of the object, I should be able to hook up two lcd displays at once. If I have some time this week, I will make a second lcd cable and try it.

I must thank everyone so far for their efforts for a unified 8 and 4-bit library, but wouldn't it be prudent to also support a serial version of this new library? I was thinking of just an undertaking...but many wonderful people here have already started and I wouldn't dream of encroaching upon their work

As far as I know, different serial LCDs have different protocols, which makes it hard to write a single library to talk to them. But if anyone wants to take a shot at creating a nice system for supporting multiple protocols and selecting between them, that would be cool.